Process of refining oil



July 211 11926.

B. v. sToLL PROCESS OF REFINING OIL Filed Oct. 1922 2 Sheets-Sheet 1 B. V. STOLL PROCESS OF REFINING OIL Filed Oct. 6, 1922 LSQBE? 2 Sheets-Sheet 2 J 1,593,275 PATENT OFFICE.

nanny v. STOLL, or noursvmnn, xnn'rucmr.

PROCESS OF REFINING OIL.

Application filed October 26, 1922. Serial No. 597,010.

This invention relates to an improved process of cracking oils and is designed as an improvement on the process disclosed in ilgy lPatent No. 1,492,273, issued April 29,

The primary object of the present invention is to provide forthe more thorough and effective cracking of the crude oils whereby to materially increase the quantity as well as the .quality of the refined products ob, tained.

In previous processes the crude oils have been subjected to heat and pressure of degrees sufliciently high to effect a cracking of the oils but I have found that much better results may be obtained by maintaining the oils at a relatively high cracking temperature and pressure in the heating coils and then delivering .the oils into the still at a cracking temperature and pressure which,

' however, are lower than those to which the oils are subjected in the heating coils, and therefore it 'is another important object of the invention to provide means whereby these conditions may maintained.

Another object of the invention is to provide for the continuous carrying out of the process and efiecting a more thorough and complete cracking of the oils by maintaining a constant flow of a maximum volume thereof through comparatively few heating coils and recirculating the oils after they have passed into, the still, and by operating in this manner I am enabled to avoid the necessity of employing a great number of coils, and generally obtain better results.

Another important object of the invention is to crack the oils under such conditions that there will be a' minimum amount of free carbon deposited thus effecting a saving in time and labor in' maintaining the appabe established and rams in operation.

In the accompanying drawings:

Figure 1 is a view partly in elevation and partly in section illustrating the apparatus embodying the invention;

Figure 2 is a detail vertical longitudinal sectional view through the still of the apparatus;

Figure 3 is a vertical sectional view on the line 3-3 of Fig. 2;

Figure 4 is a detail vertical sectional view on the line 4-4 of Figure 2.

In the drawings the numeral 1 indicates in general a furnace which may be of any desired construction and within which is arranged a coil 2 through which the crude oil or petroleum is continuously passed and within which it is heated to the desired degree of temperature. Oil is supplied to the 2 at the upper end of said coil, and a pipe 5 leads from the lower end of the coil and may be carried directly to the still or it may lead into a tar trap indicated in general by the numeral 6. This tar trap, when employed, will preferably comprise a pipe of large diameter or a drum indicated by the numeral 7, and a pipe 8 will be led from the lower end of the trap and provided with a draw-off valve 9 and also preferably with a blow-off valvelO to afford-safety in the event of an abnormally high pressure in the coils 2. A pipe 11 leads from the upper end of the trap 6 and is designed to conduct the heated oils to a pipe 12 which leads to the still indicated in general by the numeral 13. A by-pass pipe 14 may be connected with the pipe 8 and with the pipe 12, and if desired a release valve 15 may be arranged within the pipe 14 designed to open at a predetermined pressure. A thermometer 16 and a pressure gage 17 are preferably ar ranged in the length of the pipe 12, and at a point between the juncture of the pipe 11 with the said pipe 12 and the point of communication of the pipe 12 with the still 13,

there is interposed in the pipe a release valve 18 designed to open at a predetermined pressure, ordinarily 150 lbs. This valve is not illustrated in' detail herein but constitutes the subject-matter of my copending application filed October 26, 1922,

Serial N 0. 597,009. In the present disclosure it will suflice .to say that this valveis designed to open at a pressure of approximately 150 lbs. to the square inch, which is ing delivered from the coil into any suitable receptacle 21, and interposed in the pipe 19 is a release valve 22 preferably of the same type as the valve 18 and designed to maintam 'a pressure within the still 13 of a proximately 100 lbs. to the square inch, 1;

i this point it will be evident that the presat a constant pressure and temperature during the cracking processes heretofore employed.

In order to further assist in the cracking of the oils, the pipe 12, at its end which is led into the upper portion of the still 13,

- is provided with'a head 23 from which a number of nozzles 24 are led in a downward direction, and these nozzles are arranged at their lower ends preferably to discharge against the concave upper surface of a battle and spreader 25- comprising a plate curved betweenits lon 'tudinal edges and supported in spaced re ation to the discharge ends of the nozzles 24 preferably by anchoring fingers 26 secured to the nozzles .and to the said upper surface of the baffle plate. As the jets 0 against the plate 25, they will be broken up and sprayed against the wall of the still 13 in a finely divided state. In the process forming the subject-matter of my patent jets of steam are directed against the incoming jets of oil to disintegrate the same but I have found that in the present process it is unnecessary to employ steam and that equally as good results if not better results.

ma be obtained.

pipe 27 leads from the bottom of the st1ll 13 to a pump 28 which is of greater capacity than the pump 4, and the uncrackedbils which are'thus taken from the still, are delivered by the pump through a plpe 29 to the pipe 3 from whenceth'ey pass to the coils 2. Thus, with the two compressors 4 and 28 in continuous operation, crude oil from the source'of supply is fed in regulated volume to the coils 2, and a rapid circulation of the crude oil and also the oils drawn from the still 13, is maintained in the coils 2 through the operation of the compressor or pump 28. In this manner I amenabled to maintain constant rapid How of oil under the proper high degree of pres-.. sure, through a relatively small number of coils. Also by drawing the oils from the still 13 and repassing them through the coils 2,. I am enabled to e'fiect' a cracking of such 011s as are not'cracked atthe time of their oil are discharged from the nozzles initial passage through the coils, thereby In the carrying out of the process, the fire in the coil furnace 1 is controlled so as to maintain the oil in the coils 2 at a temperature of between 700 :and 750 F. In the coils the pressureis as before stated, approximately '150 lbs. to the square inch. The temperature in the still 13 is maintained'at between 400 F. and 500 F. and the pressure at approximately 100 lbs. to the square inch. 1

The process and apparatus 'of the invention are also applicable in treating crude lubricating oils to convert them into low cold test oils, and in this connection I have found that a lubricating oil having a cold test of, for example, 50, if treated by the process, may be refined so as to tst at zero. In treating such oils, the rate at which the oils are passed through the feeding coil has been found to determine the extent to which they may be refined; that is to say, if the oil is passed through rapidly, its cold test will not be reduced to as great a degree as if passed 7 been treated by the process described, they are finally sub'ec'ted to treatment by sulphuric acid, or by a process of filtration, or by both.

Preferably, the coils 2 are led through the walls of the furnace 1 and are provided with return bends having clean-out plugs 30 providing means whereby the coils may be inspected and, if necessary, cleaned out,

My process is distinguished from the processes ordinarily followed by the fact that the oil is subjected to a sudden change of pressure, it being first subjected to a high pressure and 'su denly released at a much lower pressure. The result of this sudden reduction in pressure may be compared with the effect produced by striking a'rock a sudden blow to crumble it as distinguished from the exertion of pressure applied slowly. Having thus described the invention, what is claimed .as new is: v

The process of'cracking oil which comprises subjecting oil in a heating coil to a cracking temperature of from approximate 1y 700' F. to 750 F. undera pressure of approximately one; hundred and fifty pounds per square inch, and allowing the product to' expand in,-a"cylin der still at a temperature of approximately 400? F. to 500 F. under a pressure of approximately one hundred pounds per s uare inch.

In testimony whereof Ia I? signature. I p 

